A printing system includes a print media having two sets of test patterns formed or printed in at least two margins adjacent a content area on the print media. The two sets of test patterns are separated by a pattern distance and at least two test patterns in each set of test patterns have a different number of marks. Two integrated imaging systems are disposed opposite the print media and are mechanically tied together and separated by a fixed distance. The integrated imaging systems substantially simultaneously capture images of the two sets of test patterns. An image processing device can process the images to determine if one or more size variations have occurred in the print media in the in-track direction.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A printing system comprising: a print media; two sets of test patterns formed or printed in margins adjacent a content area on the print media and separated by a pattern distance D P , where at least two test patterns in each set of test patterns have a different number of marks; a pair of integrated imaging systems disposed opposite the print media and mechanically connected to one another and separated by a fixed distance D K , wherein each integrated imaging system is configured to provide a defined integration time for capture of one or more images of each of the set of test patterns to produce an optically averaged image of each of the set of test patterns, and wherein each integrated imaging system in the pair of integrated imaging systems comprises: a housing; an opening in the housing for receiving light reflected from the print media; a folded optical assembly in the housing that receives the reflected light and transmits the light a predetermined distance; and an image sensor within the housing that receives the light and captures one or more images of a respective set of test patterns; and an image processing device for processing the optically averaged images of each of the sets of test patterns to produce test pattern signals for each set of test patterns and for comparing each test pattern signal to a respective reference test pattern signal to determine whether a size variation has occurred in the print media.
2. The printing system as in claim 1 , wherein the two sets of test patterns comprise two sets of non-objectionable test patterns.
3. The printing system as in claim 1 , further comprising a storage device for storing one or more reference test pattern signals.
4. The printing system as in claim 1 , further comprising an image processing device for processing the images of the two sets of test patterns to produce a test pattern signal for each set of test patterns and for analyzing respective test pattern signals to detect a size variation in the print media in the in-track direction.
5. The printing system as in claim 4 , further comprising a storage device for storing test pattern signals.
6. The printing system as in claim 1 , further comprising at least two vent openings in each housing, one vent opening for inputting air or gas and one vent opening for outputting exhaust.
7. The printing system as in claim 1 , further comprising a vent opening in the housing for receiving air or gas.
8. The printing system as in claim 7 , wherein the opening in the housing is used to output exhaust.
9. The printing system as in claim 1 , further comprising rollers for transporting the print media through the printing system.
10. The printing system as in claim 9 , further comprising a motion encoder connected to at least one roller, wherein the motion encoder is adapted to output a signal proportional to a fixed amount of incremental motion of the print media.
11. The printing system as in claim 9 , wherein each integrated imaging system in a pair of integrated imaging systems is disposed over the print media at a location where the print media is transported over a roller.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
May 31, 2012
May 27, 2014
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